1. Field of the Invention
The present invention relates to texture mapping method and apparatus for jointing a plurality of texture images and mapping them on a surface of a three-dimensional model.
2. Description of the Related Art
In computer graphics, one example of a method of displaying a three-dimensional object is texture mapping for overlaying a two-dimensional color image including color and pattern, namely, texture image to a surface of an object expressed by three-dimensional shape data. For example, in order to execute texture mapping along the whole periphery of a three-dimensional model, it is necessary to joint a plurality of texture images captured from different directions and map them. Adjacent texture images are captured previously so as to have an overlapped portion.
In the case where an object is modeled by a three-dimensional shape input device utilizing an optical cutting method, three-dimensional shape data always include an error which differs in degree due to specification of devices. Moreover, as a method of expressing the three-dimensional object, there is a method of generating a spline curved surface model by means of triangular Bezier based on polygon mesh created by VI (Volume Intersection) which is one kind of a silhouette method and fitting the curved surface to a visual line passing through a silhouette (Steve Sullivan and Jean Ponce, “Automatic Model Construction and Pose Estimation From Photographs Using Triangular Splines,” IEEE Trans. PAMI, 20(10), pp. 1091-1097, 1998). In the fitting of the curved surface, a curved surface cannot occasionally express a precise shape of an actual object. When texture images obtained by photographing an object are mapped for three-dimensional shape data including an error, as an influence of the error, a displacement occurs between a boundary (outline) of an image obtained by projecting three-dimensional shape data onto a two-dimensional image (texture image) and a boundary between an object in the texture image and a background. As a result, there arises a problem that texture mapping including a background color is carried out.